This invention relates generally to grounding and more particularly to ground leads and support bushings, which create a grounding condition for an electrical apparatus.
Grounding is the intentional electrical connection to a reference-conducting plane, which generally consists of a specific array of interconnected electrical conductors referred to as the grounding conductor. Grounding provides a zero point for an electrical conductor system.
Typically, grounding from a printed circuit board (xe2x80x9cPCBxe2x80x9d) to a grounding feature utilizes two separate components. These two separate components provide a grounding path from a PCB, or another electrical device, to a grounding feature. The ground lead and support bushing are individually manufactured and processed, and subsequently bolted or screwed together when inserted onto the grounding feature. The support bushing provides structural support for a housing, which contains the ground lead contacted to the PCB. The resulting combination of the support bushing and grounding lead contacted to the PCB is subsequently bolted to a grounding feature. In one example, automobiles serve as a grounding feature for a PCB that is contained within a housing. To create a grounding path between the vehicle and the housed PCB, a ground lead is press fit or soldered to the housed PCB. The other end of the ground lead has a ring which fits over the top of the support bushing, which is contained in a mounting pad of the housing. To connect the housing containing the PCB, a bolt goes through the mounting pad, and then passes through the ring of the ground lead and through the support bushing and into the vehicle. As a result, the ground lead and support bushing provides an electrical connection from the PCB to the grounding feature. An electrical current passes from the PCB into the ground lead, which is soldered or press fit to the PCB. Then the electrical current passes to the support bushing, which is contacted to the grounding feature.
In order for grounding to be complete, the bushing and ground lead must be in contact to create a completed grounding path. If there is no contact between the support bushing and the ground lead, the grounding path from a PCB, or another electrical device to a grounding feature will be broken. If there is a gap between the support bushing and the ground lead, a non-grounding condition will be created. In view of the foregoing, there is a need to have a permanent and reliable contact between a support bushing and a ground lead.
The present invention provides apparatus and methods for constructing a support bushing and ground lead. In one embodiment, a ground lead and support bushing are constructed for insert molding by blanking and forming it from one piece of material to form a single integral and gaplessly continuous piece.
In another embodiment, the one-piece ground lead-support bushing provides a grounding path from a PCB, or another electrical device, to a grounding feature. One exemplary application for the one-piece ground lead-support bushing is in an automobile, where the ground lead-support bushing is assembled to the vehicle.
Another aspect of an embodiment of the invention is that the one-piece ground lead-support bushings are manufactured and processed from the same sheet of material.
In another embodiment, a carrier strip of material is blanked to provide a flat pattern of the one-piece ground lead-support bushing. Then the flat pattern is sent through a series of forming processes, which give the one-piece support bushing-grounding lead a shape that can be used in a variety of grounding applications.